1. Field of the invention
The present invention relates to a method of resistive sheet transfer printing and an electrode head used in the field of image-forming technique for producing a high quality image with high speed and high sensitivity.
2. Description of the prior art
A high-speed production of a full-color image is suitably realized by a resistive sheet color transfer printing technology by means of current-carrying using a recording member (including an ink sheet made of a resistive sheet carrying thereon an ink containing a pigment or sublimable dye and an image receiving member having a color development layer in the surface thereof) and an electrode head. The electrode head has a multistylus thereof held by a plurality of insulating support members generally made of a thermo-setting resin, glaze or ceramics such as alumina. The same materials is used for both inside and outside of electrode pairs.
In a case where a binary recording image at a high speed is realized by using a sublimable dye as the color materials in order to produce a full color and high quality image, a conventional electrode head poses the following problems to be solved owing to the requirement of a high recording energy:
The insulating support members for the heads can not be optimaized in a thermo-mechanical characteristics;
Realization of high recording speed and sensitivity can not be fully accomplished;
Recording dots is not optimized and stable transit of continuous recording is not fully and practically realized. Especially, under a high speed recording, that is, under a high temperature and pressure, wearability of the insulating support member for the head on which surface the resistive sheet of the recording member is sliding, has not been controlled, so that there is a big problem that contact failure between the multistylus head pairs and the resistive sheet occurs, there by making it difficult to subject the resistive sheet to continuous record running and causing a image an inferior quality. Furthermore, the thermal constant of the insulating support member has not been controlled, so that for instance if the insulating support member having a small thermal diffusion coefficient is used for the head, sensitivity would be improved but the recorded image color would become less clear and the resolution thereof would be reduced due to heat storage. On the contrary, if the insulating support member having a large thermal diffusion coefficient is used, sensitivity would be lowered and also the feature of resistive sheet transfer printing would be lost.